


Day 6: eggs & breeding / Undersea Creatures

by elwon



Series: TentaTodd [7]
Category: Batman - All Media Types, DCU (Comics)
Genre: Aquaman 2018 au, Breeding, If I've missed a tag pls tell me ty, M/M, Merman!Dick, Octomer!Jason, Tentacles, Tentatoddweek, Weird merman sex, except they can both breathe in the air and they're not royalty
Language: English
Status: Completed
Published: 2019-02-15
Updated: 2019-02-15
Packaged: 2019-10-28 11:44:58
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,500
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17786750
Author URL: https://archiveofourown.org/users/elwon/pseuds/elwon
Summary: The merman’s fins are so thin that they’re almost translucent, and Jason worries that if he touched one he might destroy it by not being gentle enough. Not that he’s confident enough to get anywhere near the pretty merman currently sunning himself on the roof of the cave Jason calls home.





	Day 6: eggs & breeding / Undersea Creatures

The blue merman with the fancy tail is back again on the outcropping of rocks that makes up the tiny islet in the middle of the ocean, for what must be the fourth time in as many weeks. Jason hides in a tidal pool, feeling his heart beating faster, his lower eighth arm stiffening despite his best attempts to look elsewhere and think of other things. The merman’s fins are spread over the rocks and glistening in the sunshine. They’re so thin that they’re almost translucent and Jason worries that if he touched one he might destroy it by not being gentle enough. Not that he’s confident enough to get anywhere near the pretty merman currently sunning himself on the roof of the cave Jason calls home.

Jason’s eyes kept get drawn back to the thick set of gills on either side of the merman’s flanks. They flare open almost in invitation with the lapping of the ocean water against the side of the islet, and Jason can’t stop himself from imagining sliding his eighth arm inside, fertilising all of the eggs inside him. 

Jason ducks down further into the warmer water of the tidal pool, letting it calm him. The cooler ocean water might be quicker, but there’s something about the sun heated pool that’s more comforting. He curls his top two arms around his lower eight, trying to take up as little space in the pool as he can, which is not an easy feat considering the length of his lower arms. There’s a splashing noise and Jason lifts his head only to see the pretty merman breaking the surface of the pool. His fins fan out, taking up nearly all the available space and Jason takes a small inhale of water as one brushes his arms. It feels like the gentle touch of the human cloth, that’s still attached to the bow of the wrecked ship that hides the entrance to his cave under the water.

Jason stares as the pretty merman’s face comes into view, his fins billowing around him in the water. His eyes match the blue of his tail perfectly in contrast to the inky black hair on his head. The merman blinks in surprise at seeing Jason there, and Jason unfurls himself to take up more space and look more like the threatening predator he actually is. He suspects it would be more effective if two of his arms weren’t reaching out to trail their tips along the fins in front of them. It’s a slightly embarrassing problem that happens when you have nine brains in different places.

“Oh. Sorry, I didn’t know this pool was occupied... I would have said hello!” The merman smiles at Jason, seemingly unaware he’s potentially in danger. “I’m Dick.”

“...Jason.” Jason winces; his voice is rusty from not talking to anyone for a long time. His species is notoriously anti-social, to the point that many in the fisherman kingdom don’t believe they exist, and here is this merman, who’s actively trying to engage him in conversation instead of running away.

“Nice to meet you. You come here often?” Dick says, tilting his head, causing the water to lift his shaggy black hair up around him like a halo. 

“Uh.” Jason coughs awkwardly, letting his arms spread further out. “I live here.”

“This is where you live? But there’s nothing here!” Dick pauses, and his fins float around him making him seem almost illusionary. “I mean it’s a great sunning spot, and somewhere to pause on a long journey, but there’s no shelter from humans...”

“Cave. Underwater.” Jason shrugs, extremely grateful that his top two arms are controlled by the brain in his head. At least he can always rely on _them_ to do what he wants them to.

“Oh. Nice.” Dick smiles again, and Jason shifts uncomfortably. Somehow, he’s even prettier when he smiles. “I’ve never met an octomerman before. I wasn’t sure you guys actually existed or were just myths!”

“We don’t like others much. Prefer to be alone.” Jason’s arms spread out underneath him, increasing the space he takes up in the pool until he’s bigger than Dick, who’s only taking up space thanks to his fins.

“Oh. No octomermaids here, then?” Dick says with an interested quirk of his mouth. There’s a look in his eyes that Jason doesn’t recognise, although he thinks it might be hunger.

“Poseidon’s beard, no!” Jason shudders at the thought. “Can’t think of anything worse than that.”

“Really? Not even for mating?” Dick grins, tapping at his bottom lip with a finger. Jason’s eyes follow that finger and he can’t help but wonder if those lips are as soft as they look.

“Oh yeah, I’m totally into cannibalism.” Jason rolls his eyes, voice dripping sarcasm. “Except wait, I mean the opposite. I’ll pass, thanks.” 

“Oh, that cannibalism thing’s true?” Dick blinks at him and swims in closer, surrounding Jason with his long thins fins. “I can see why you’d pass.”

“Uh huh.” Jason decides that getting out of the pool before he does something stupid, like believing that wrapping all his arms around Dick, and taking him away to play with him over and over again, is a good idea. He pushes back and up out of the water, walking across the plant strewn rocks to the ocean.

“Wait!” Jason hears splashing following after his much smoother exit from the water and he twists to look back, and sees Dick pulling himself out of the pool and dragging himself across the rocks. Jason pauses, his lower arms pushing him up higher into the air as Dick crawls up to him. “Can I come with you?”

“Why?” Jason says confused, even as his nearest arm sneaks out to wrap the tip around Dick’s wrist. Jason refuses to blush, even though Dick’s skin and the delicate pattern of scales up along his chest and arms feel soft and smooth under his suckers.

“I’m curious?” Dick says, his cheeks tinting a faint blue colour under the golden sparkles of the scales scattered over his face. “I’ve never seen an octomer’s home.” His gaze flicks down and away from Jason’s. Jason has the distinct feeling that Dick’s not telling the entire truth, but he also knows that in the large cave of his home, he’ll have the upper arms in the situation; given that most of the cave is not actually submerged, only the entrance and a fairly shallow pool that fills around a third of it.

“I... guess.” Jason shrugs, ignoring how another of his arms leans forward to help Dick off his stomach. Jason walks over to the edge of the cliff and jumps down, Dick going down into the water with him while he holds on to him.

Jason swims deeper until he finds the cave entrance near the sea floor, swimming along the tunnel with ease and familiarity despite the twists and turns, until the tunnel starts rising, and he emerges into the large pool of his home cave. He lets go of Dick and climbs out of the water, walking over to the rope pulley he uses to close off the small opening in the ceiling of the cave, letting more light in. He walks back to the pool, waiting until Dick starts to approach the surface.

Dick’s head rises out of the water and he comes over to the edge of the pool, resting his arms on the flat stone, looking around with clear interest. The cave is filled with things that Jason’s scavenged from shipwrecks, the flotsam and jetsam of the surface world; but a few things are clearly from the undersea kingdoms, like a set of admittedly bashed up multi-limbed armour, clearly for octopods, which is lying slumped over in the corner, and a communicator to call the fisherman kingdom in emergencies, and entertainment monitor which receives all the atlantean channels, set up in the shallower pool, next to Jason’s sleeping area. 

A flat rock works as a table, covered in old wicker baskets filled with nets and old bottles. A few fish skeletons and empty crustacean shells litter the table, along with some dried seaweed. The cave wall by the entrance pool is undecorated, but the other portions of the egg shaped cave are filled with things to look at. One section is dominated by a large red sail that Jason took from a recently wrecked yacht. It hadn’t had any corpses on board, to Jason’s relief. The yacht had a strange sail that didn’t feel like any material that Jason knew, but he liked the colour, so he’d taken it. Another part of the cave is decorated with a large printed cotton picture of a stylised big wave, it may not have the luminescence of the undersea kingdoms art, but Jason likes it for the little details, like the boat full of men that you miss on first look.

The rest of the cave walls are decorated with the bio-luminescent moss that naturally grows there, and the paint that Jason’s made up from various plants and small squid he’s caught. He likes to doodle on the walls when he gets bored of the entertainment programming during the day, and he’s finished the week’s chores already.

It’s only as Dick looks around that it occurs to Jason to feel slightly embarrassed at the home that no one else has ever been in. It’s strangely exposing to have someone else looking in on his things and how he lives his life. It’s something he’s always avoided, and one of the reasons he left the undersea kingdoms to live in this isolated cave by himself.

“Your place is cool!” Dick says after what feels an age. Jason blinks and shifts with awkward nervousness.

“Uh. Thanks.” Jason turns to clean up the table, utterly unsure how to do this hosting thing. “I don’t really have anyone over, so...”

“I like it. Your wall hanging is interesting, I’ve never seen anything like it.” Dick says, boosting out of the water to roll his tail over the edge and sit on the floor. “It doesn’t glow or move. It makes a nice change!”

“Thanks. I mean, I didn’t make it. But yeah...” Jason shrugs, walking over to sit next to Dick and let his lower arms slip back into the water. “I did the painting though.”

Dick turns to look at the wall covered in paint. “Oh cool, you can see your progression from when you started to now, I guess? You’ve really improved.”

“Uh. So...” Jason flicks his gaze down into the water, trying his best to avoid staring at Dick’s lithe body and the way his fins spread out over his floor. “What do you like doing, apart from sunning yourself on my islet?”

“Working. I’m a dancer with the Royal Troupe, and I really love my job. We perform nearly daily.” Dick says, lighting up with enthusiasm. “Other than that, I love being with my friends.”

“No hobbies?” Jason curls his arms in the water, watching them float in the gentle current and gently brush against Dick’s fins. They don’t tear at the light touch and Jason feels a sense of relief.

“Not really. Dancing’s my life. Practicing, rehearsing and performing don’t really leave a lot of free time. Maybe one day you’ll see me perform?” Dick flexes his tail, making his fins swirl around Jason’s arms flirtatiously.

“Huh. Maybe. You never know.” Jason glances over at Dick, picturing him on stage with others, all twirling around each other in a breathtaking show of skill and precision to music.

“So how did you end up out here? You’re a far way out from the borders of the kingdom.” Dick says after a pause.

“I like the solitude. After my mother died, I wanted to get away from everyone else, and most don’t come out here because it’s too close to the surface world.” Jason shrugs. “The fishing boats do pass by here, but they avoid this rock, so it was perfect.”

“You don’t have any other family?” Dick lifts a hand to push his wet hair back from his face and the light from the glowing moss catches on his golden scales.

“No. My mother was atlantean and my father was a fisherman. As far as I know they were both alone in the world too. But that’s why my top half looks more atlantean.” Jason says gesturing to upper half, that looks more human with black hair on his head and ‘human’ skin colour. “And the lower half is clearly octomer.” Jason gestures to his deep red lower arms.

“Oh. I’m the opposite, but the same. My mother was a fisherman and my dad was atlantean.” Dick grins. “Hence my ‘quote’ amazing hair and fabulous fins!” Jason snorts at Dick’s wide grin.

“Speaking of being far out, you’re a long way from home. How come you’re all out here by yourself? I would have thought a pretty fish like you knew better than to come out here without any of your podmates for safety.” Jason says, trying not to stare at the delicate, almost transparent fins that edge Dick’s ears.

“I needed to get away and clear my head. It’s kind of personal...” Dick sighs, staring down in to the water, his shoulders slumping under the weight of his personal business. “Would you mind if I unloaded on you for a bit?”

“Sure, it’s not like I’m gonna tell anyone.” Jason says as one of his lower arms rises in the water to curl around the lowest point of Dick’s tail to comfort him. Sadness doesn’t look right on Dick’s face, Jason thinks. He may only have known Dick a short time, but he can tell that, at least.

“Well, it’s... OK so, I’ve got to the point in my life where I want to have children. But all my long-term relationships have ended. I’m friends with them, but it’s not the same. I’m not really looking for love anymore, I guess? And everyone I’d trust to have a child with is either in a relationship already, or doesn’t want kids.” Dick sighs, twisting to let the end of his tail slide into the water. “So I go for a long swim to let my troubles fade for a while, because all I want is someone who’ll help me have kids but not expect anything from me. Just a _nice someone_ who’ll knock me up with no strings attached.”

“I’d do it.” Jason blurts out, staring at the sad downturn of Dick’s eyes. “I mean, uh. If you couldn’t find anyone else, that is.”

“Really?” Dick looks over at him, startled. Jason’s not sure which of them are more surprised he’d offered, but he’s done it now.

“Yeah. I... Well, I like my life here. I don’t like being around people, but I still have that drive to have offspring like the rest of my species.” Jason shrugs, thinking out loud the reasons that this could actually work. “I know it’s sudden, but it might solve both our problems... I get to sire a child or two, you get the children you want, and neither of us would have to change our lives too much to do it.”

“Oh, wow.” Dick murmurs, still surprised, but also with a little intrigue. 

“I’d be happy to be that friend you visit every once in a while for a vacation.” Jason wonders if he’s been too aggressive. One of the downsides of always being alone is that you forget what’s too much. “Uh. Only if you want, though. Whenever you want, if you do want.”

“I do.” Dick says firmly, looking at Jason with confidence.

“Because it’s an open offer... Wait you do?” Jason stops, he’d thought Dick would say no, that Jason had rushed into offering, but thank you for being willing to help.

“Yes!” Dick bites at his lips to try to stop a smile at how flustered Jason’s become from taking over his face.

“Uh... Really?” Jason blinks at Dick, trying to regain control of his calm. The thought that Dick might actually want Jason is... A lot to take in and process.

“Yes. You’re nice, and you’ve been kind despite being a loner.” Dick stops and flushes a pretty pale blue. “You’re attractive, too. I’m sure we’d make beautiful children.”

“Well, if they look anything like you they certainly will be.” Jason says, and Dick flushes again, a glint of happiness in his eyes that looks _right_ there.

“You’re so sweet.” Dick leans over a little into Jason’s space. 

“So... When do you want to do this?” Jason says, already trying to plan when the best time would be. Surely Dick wants some time to prepare his home?

“No time like the present!” Dick says brightly, with a huge smile on his face. Jason only has moments to be dazzled before Dick’s launching himself at him and wrapping his arms around Jason’s shoulders to kiss him breathless. Jason takes the weight of Dick in his arms, wrapping his lower ones around Dick’s tail and leaning back until Dick’s resting on top of him.

“Are you going to wrap me up?” Dick says with a delighted grin. Jason smirks back and rolls them over, so that Dick’s flat on his back on the cave floor. He wraps five of his lower arms around Dick’s tail, being careful of the fins, right the way down to the very tip. He uses two to brace himself against the floor on either side of them. His eighth lower arm he lets stiffen up slowly, ready to go inside Dick. His upper arms slide under Dick’s shoulders, one resting under the small of his back, and the other cradling Dick’s neck. 

They kiss for while more, until Dick’s doing his best to squirm in the tight suckered hold of Jason’s arms. When they stop kissing for long enough for Jason’s eighth lower arm to move between them, Dick’s flushed a pale blue all over his face and chest, and Jason feels a sense of pride at affecting the beautiful merman so much.

“So, uh, which hole do I use?” Jason says hesitantly. The few conversations he’d ever had about reproduction, rather than sex for pleasure, had only covered female octomers. As far as he’s aware, it’s not the same with a merman.

“Which... Hole do you use?” Dick says slowly staring up at Jason.

“One,” Jason points at Dick’s slit with his eighth lower arm, “Two, Jason gestures to Dick’s mouth “Three, four, five,” Jason drags the arm over the gills on Dick’s left side, “Six, seven, eight?” he taps at the gills on Dick’s right side.

“One.” Dick says with a look on his face that’s a mix of concern and amusement as he pushes Jason’s eighth lower arm down to his slit. “Always one.” 

“Right. I’ll remember that.” Jason says nodding seriously. It makes Dick laugh in his arms, and the vibrations along his tail feel nice under Jason’s suckers.

Dick’s slit opens up easily under the light touch of Jason’s arm. A small cock starts to slip out at the top of the slit, and Jason slides his arm under it and into the sheath of Dick’s body. It’s tight and warmer than Jason was expecting. The walls of Dick’s channel squeeze down on his arm as he slides it in deeper.

“Fucking trench, you’re so tight.” Jason groans out, feeling the tip of his arm reach the end of the sheath. There’s a tight ring of muscle at the end, the cervix Jason thinks, and he lets the tip of his arm rest against it.

“No, you’re just big.” Dick moans, biting his lip. There’s a glazed look of pleasure on his face already that Jason really likes. 

“Are you sure?” Jason says with a grin. He lets a load of his seed shoot from his arm right up against the ring of muscle. Technically the deed is done now, but that look on Dick’s face is one he wants to keep seeing there.

“Oh trench me, you’re in so _deep_!” Dick gasps, doing his best to buck his whole body, but Jason holds him still.

“Is that good for you?” Jason says, studying the way Dick’s breath hitches and listens for the contented sighs that come from his mouth. He pulls his arm out a little and thrusts it back in, rubbing along the underside of Dick’s cock teasingly.

“Yes, Jason, so good!” Dick sighs, and the heavy gust of air ruffles Jason’s hair pleasantly.

“You like that?” Jason keeps thrusting, and sends another load of seed deep inside Dick. “Like me fucking my babies into you? Breeding you so full?”

“Yes, please, do it!” Dick whines, trying to wriggle futilely. It’s really quite cute to see him do that.

“I already have. But I guess I could do more, just to be sure.” Jason grins, pumping his arm in and out of Dick and feeling the tight channel loosen for him. Each time he can slip a little more in and curl his arm into a coil, all while leaving the tip where it needs to be.

“Oh Jason... You’re too good to me.” Dick gasps out between two apparently really good thrusts.

“You want that? To be so full it leaks out of you?” Jason lowers his voice, speaking right into Dick’s ear, conspiratorially.

“Yes!” Dick’s arms tighten around Jason’s shoulders, and his nails press in against the skin of Jason’s shoulders. It stings a little, but Jason likes it.

“It’ll make you so slippery inside. Even with how tight you are.” Jason promises, tightening his upper arms around Dick’s back.

“You say the filthiest things...” Dick grins, trying to push his slit closer to Jason. “I like it.”

“You think that’s filthy?” Jason snorts. And OK, well, he’s a young healthy male that lives alone; sometimes he watches the more risqué channels broadcast from Atlantis. “That sounds like a challenge.” 

“Maybe it is...” Dick gasps, as Jason fills him with another load of come.

“Hmmm. Should I keep you fucked full and pregnant all the time, would you like that?” Jason says, remembering the one adult movie he’d watched that had breeding in it as a plot point. Jason hadn’t found it all that sexy at the time he watched it, but some of the dialogue had stuck with him.

“Poseidon’s beard!” Dick cries out, clamping down on Jason.

“Should I take that as a yes, Dickie?” Jason pushes more of his tentacle inside Dick, letting it coil up thicker and thicker. Dick’s getting looser and more slippery with every burst of come. But Dick seems to love the stretch and wetness, given how he’s gripping at Jason’s shoulders. And he’s not the only one.

“Jason!” Dick says, with obvious need in his voice. It makes Jason’s chest tighten and gives him a sense of power that he finds he really enjoys.

“Hmmm? Do you need something?” Jason smirks, keeping his tone casual, as if he’s not slamming his coiled arm in and out of Dick’s slit and making him moan and gasp.

“Please... Please, I need to come.” Dick begs, looking up at Jason with the most needy, hopeful expression on his flushed blue face.

“I’m not stopping you.” Jason grins, and focuses on rubbing his arm right at the base of Dick’s cock.

“Please!” Dick sounds almost frantic, and something occurs to Jason when the pitch of his voice rises.

“Oh, are you one of those types that needs permission?” Jason grins; he likes this side of Dick. He squeezes the back of Dick’s neck, and then slides his hand up to cup the back of his head.

“Yes, please, please, Jason!” Dick sobs, running his nails across Jason’s back, leaving little scratches in their wake.

“Well, in that case... I want you to show me how grateful you are for me getting you pregnant. I want you to come for me, show me how much you like this.” Jason says, putting something hard into his voice that makes Dick tense up in just the right way.

“Jason!” Dick screams as his eyes roll into the back of his head and he bucks hard, clenching down on Jason’s arm. He slams his head back towards the ground, only avoiding hurting himself due to Jason’s hand cupping his head. Thin white liquid shoots out of his cock between their chests and Jason lets one final burst of seed come out of his arm inside Dick. 

Dick goes limp in his arms, breathing hard and flushed a deeper blue than Jason’s seen so far. Jason eases his arm slowly out Dick’s slit, and then rolls them over, so that he’s lying on his back, with Dick resting on top of him, still held tight in his arms. 

“Oh wow. It really is leaking out of me.” Dick giggles. “Mmm. I feel so good. I just want to nap.”

“Hmmm. You did take quite a pounding. I guess you deserve one.” Jason grins, sitting up and forcing two of his arms to let go of Dick long enough that he can walk them over to his sleeping pool. It only works when he reminds them that the sooner they let go, the sooner they can wrap back around him and keep Dick with them.

“Ah! Oh, that’s an odd sensation...” Dick laughs as Jason walks over to his pool and slides under the water, to his sleeping bay. “I kind of like being carried in the air though.”

“Oh yeah? I suppose I can do it again if you really like it.” Jason lays them both down on the bedding, and Dick sighs happily.

“Oooh, this is comfy. Where did you get it?” Dick runs one hand down the soft surface bedding.

“Same wrecked yacht as the red sail. It’s modern, went down last year, so it’s some fancy surface technology, I guess.” Jason says, squirming down the bed a little. His arms lazily slide around Dick’s now free floating fins.

“I really like it.” Dick hums happily, squirming a little in Jason’s arms now that he’s loosened his grip.

“Cool. You’re welcome to come over at stay whenever you want, Dickie.” Jason says, watching how Dick’s fins begin to float in the sway of the water. “After all, we want to make sure you’re properly knocked up, don’t we.”

“Careful. I might just take you up on that.” Dick says with a slight yawn. He relaxes into Jason’s body perfectly.

“I wouldn’t mind.” Jason stretches his upper arm out, sliding it underneath his head.

“Yeah?” Dick looks up at him with a small pleased smile. 

“Yeah.” Jason says, returning the smile easily.

“Well then, I guess you’re going to be seeing a lot more of me.” Dick wiggles, resting his cheek on Jason’s chest.

“Good.” Jason lets his fingers tangle into Dick’s soft and shaggy hair. “I’ll look forward to it.”


End file.
